The objective of this research program is to determine at the electron microscopic level the topographical distribution of carbohydrates on membranes of the pigment epithelium cells and photoreceptor outer segments of rats with inherited retinal degeneration. We will be looking specifically for changes in the distribution of carbohydrates on these membranes during the breakdown in the phagocytic process and a comparison of these membrane-bound carbohydrates or retinas from dystrophic rats will be made with normally phagocytizing retinas from genetically controlled animals. Cell surface carbohydrates will be visualized by the use of plant lectins which blind to certain sugar residues, in combination with peroxidase labeling techniques to visualize the sites of lectin binding. Further characterization of the chemical nature of the membrane carbohydrates will be obtained by testing the effects of prior proteolytic and glycolytic digestion on the cytochemical visualization of lectin staining. The nature of the protein moiety of these membrane carbohydrates will be investigated by the use of polyacrylamide gel electrophoresis in combination with specific lectin-peroxidase stains. These glycoproteins will be extracted from the gels and immunocytochemical techniques will be used to localize the individual glycoproteins in tissue sections.